The almost 9 thousand prisoners left behind in the Main Camp (Stammlager), Birkenau, and the sub-camps as unfit to join the evacuation march found themselves in an uncertain situation. The majority of them were sick or suffering from exhaustion. The SS intended to eliminate these prisoners, and only fortunate coincidences prevented them from doing so. The SS did manage to murder about 700 Jewish prisoners in Birkenau and the sub-camps in Wesoła (Fürstengrube), Gliwice (Glewitz IV), Czechowice (Tschechowitz-Vacuum) and Blachownia Śląska (Blechhammer) between the departure of the final evacuation column and the arrival of the Red Army.

The majority of the SS men on duty in the guard towers left Auschwitz on January 20 or 21. However, larger or smaller SS units continued to patrol the camp. Wehrmacht units also passed through, and joined the SS in plundering the camp warehouses. Some prisoners took advantage of the confusion and risked escape.